Electrical controller.



mimassts J. Gr. P. THOMAS. ELECTRICAL GONTRQLLER. APPLIOATI 'N FILED Fans, 1910.

1 ,OO5,084;; Patented Oct. 3, 1911.

2 SEEBTSSHEET 1.

-' Inventor J. G P. THOMAS. v ELECTRICAL CONTROLLER.

APPLICATION FILED IEIB.3, 1910.

1,065,084. Patented Got. 3, 1911.

2 SHEETS-SHEET 2.

mirnasses Invmfor J9EE? GODFREY PARRY THOMAS, 0F CHISWICK, ENGLAND.

ELECTRICAL CONTROLLER.

nooa osa.

Specification of Letters Patent.

Patented (lot. 3, 1911..

Application filed February 3, 1910. Serial No. 541,700.

To all whom. it may concern:

Be it known that 1, JOHN GODFREY PARRY THOMAS, a subject of the King oiGreat Britain, residing at 21 Ennismore avenue, Chiswick, in the county of ll liddlesex, Eng land, electrical engineer, have invented new and useful Improvements in and Relating to Electrical Controllers, of which the following is'a specification.

This invention relates to controllers for dynamo electric machines, in which the requisite changes ofconnection are effected by means of a set of pairs of contacts arranged adjacent to a drum, in such manner that suitable cams on the drum can in the required order press one contact of a pair against its fellow, and keep them in contact for the requisite timesi The present invention hasfor its object the better lubrication of the drum and the cam surfaces.

To this end the invention comprises acasing adapted to contain oil in which the drum rotates.

A further purpose of the invention is the production of a compact controller.

More particularly the invention is designed-to combine several sets of contacts with a single drum. Also the invention aims at improving the efiiciency of the controller byenabling the making of better contacts.

More specifically the invention comprises a contact so adapted that it can rock or rotate in order to bed itself down upon its fellow.

Yet another object of the invention is toprovide means for dismantling a. controller without interfering with th'e'nu'merous con:

i in the accompanying drawings in whichnections thereto.

Examples of construction are illustrated Figure 1 is a cross sectional elevation of a controller, and Fig. 2 a detail thereof being a section on the line AB of Fig. 1. Fig. 3 is .a cross sectional/elevation of a modified form.

lj nsthe drawings, 1 is the controller drum towhich are secured projecting cams 2 0 suitable length and suitably spaced relatively to one another. Beside the drum and parallel to its axis is a column 3 upon which are mounted a series of arms 4, the

tails 5 of which are connected by springs 6 to a bar 7. The arms 4 carry projecting. pins 35 adapted to bear on the surface of the drum against which they are pressed by the tension of the spring 6. These armsalso carry one set of electrical contacts.

The contact is preferably made up of a metal strip 8 separated from the arm 4: b a strip of fiber 9 between which strip an a second piece of insulating material 10 it is clamped by means of a screw 11 passing through a lug 12 formed on the arm. To the end of the thin metal strip-8 is secured the contact proper 13 and this is joined by a flexible strip 14 to a contact piece 15 secured upon an insulating bar 16. This bar carries terminals for all the contacts 13, theterminals being joined to the a propriate resist; ances or the like with wh1ch the controller has to deal. The bar 16 is itself secured upon a metal bar '17 supported upon the end plates of the casing 18 in'which the whole controller is inclosed.

To allow of the contact 13 bedding down upon the contact brush 20 it is convenient to bevel the fiber strip 9 on its upper surface, asseen in Fig. 2, so that the contact can rock a little.

The fixed contacts are supported upon another metal bar 19 which similarl rests in slots in the end.- plates of the casmg. The contacts proper comprise laminated brushes- 20 preferably formed with a prolonged outer lamination 21 arranged to receive the break;

This strip 21 may, if desired, be separated from the rest by a layer of carbon so as to introduce a resistance into the circuit before breaking, or an actual carbon break may-be provided. The brush is separated from the bar 19 by a strip of insulation 22, being held by bolts and nuts 23 bearing upon another insulating strip 24. The metal piece 25' lies in contact with the brush and carrieszthe' ter minal to which is connected the fiexible'lead 26 leading to the motor or other external part through the opening 27in the end wall of the casing 18.

Where the number of connections to be made is considerable, so that a;lar-ge num ber of contacts are required, it is convenient f to provide two columns 3, as shown in the drawing, one on either side of the main drum. The contacts 13 are necessarily of considerable width and therefore the num-" ber that can be arranged in a given length is limited. The cams 2, however, need only be of very small width and consequently by using two sets of contacts, staggered loo. 7

Q LOG relatively o to the other, with a single drum. a conslol 9 amount of space is saved.

Obviously thin even h'iore columns could be employed M. i lied.

Preferably ti e drum 1 is arranged horizontally as shown, "ilil the casing is formed with. a semicylind al recess 28 fitting the drum fairly close y, with, of course, sufficient space for This recess may be filled with oil which will be carried up by the drum in rotating and will serve the purpose of lubricating its bearings and also lessen the friction between the pins and the cams desired, rollers may be provided in place of "the pins 35. The casing be so designed as to immerse the contacts also in oil; this renders possible a diminution in the size of the contacts and does not introduce any resistance between the contact surfaces.

In the construction shown in 3 the contacts re arranged rather below "the drum tlnn above. The lower part 38 ofthe casing having a cover 39 is adapted to contain oil within which the drum 1 rotates. The flexible connections 1% extending "from the moving contacts are combined with steel springs 40, which replace the springs- 6 of Fig. 1 and serve to press the pins against the drum 1 or its cams 2. The actuul contact piece 41 is mounted upon an insulated steel spindle 42 supported in the arm 4. A beveled backing 4-3 is provided between the contact and the end of the arm 4 so that the contact may easily rock upon its shaft. This provides for the requisite bedding down upon the fixed contact 20.

The connections to the external circuit by suitable metal bars Isl, l5, joined to bolts as, which pass out through insulating sle ves 46 at the top of the casing and terminate cones 5i". Uutside the casing is provided cap 47 secured in place by across bar it-8, it? and bolts and nuts 50. Within the cap bears ribs 51 which support by means oi". insn i ing sleeves 52 the bolts and nuts 53 to which or connected the leads passing to the rhe and motors. The bolts 53 are free tot .de within the sleeves 52 and their "enlarged ends 58 have conical recesses fitting the cones 5'4". The bolts are normally pressed down to make contact with the cones by means of springs ors ring washers 59. This construction enables he controller proper to be dismounted Without interioronce-With the various connections to the external circuits. The cap 47 can be removed carrying with it all the external. connections to the bolts and nuts 53, the contacts being brol-zen of course at the cones 5?, When the cap is replaced all the contacts are immediately made without c ence of error, the cones being-pressed together by the springs or spring washers 59.- These sorings moreover, serve to allow for any d' *erencesthere may be between adjacent connector bolts so that good contact is secured in each place.

It is possible to have the controller contacts normally pressed together by the spring and separated by the cam action, or by the use of a cam groove or the like both movements may be positively controlled. If desired a controller of this form may suitably be combined with a rheostat by providing a series contact studs at one end of the casin in which the drum is mounted and attaching a bridging arm to the drum spindle. This arrangement is particularly of service in connection with the control of machines employed lor the transmission of power on motor vehicles and so forth.

What I claim is 1. The combination of a drum, cams upon said drum, pairs of pivoted and fixed contact supports adjacent to said drum, contacts upon said supports, means upon one support of each pair enabling the contact thereon to rock in a plane parallel to the pivot, and means upon the movable support enah in it o e o era-tee. the drum.

1 t b t 2. The combination of pairs cl electrical contacts, rigid supports tiereitor, means for causing one contact ot each pair to move to- ,ward or away from the ot er, and means interposed between one contact or" each pair and its support enabling said contact to rock but not yield.

3. The combination or a drum, cams thereon, pivoted contactsupports adapted to be moved by said cams, contacts rotatably mounted on said supports so as to oscillate in a plane at right angles to the plane of movemen of said. suppotts, and tinted contacts mounted adjacent to said moving contacts.

4t. combination of a drum, cams upon said drum, contact supports pivoted adjacent to said drum, spindles on said supports at right angles to the pivots, contacts pivoted on said spindles, and fixed contacts adjacent to said pivoted contacts.

5. The combination of a casing, a drum rotatable therein, cans thereon pairs of contacts adjacent to said drum,- terminals mounted independently of said contacts and connections between said terminals and the contacts.

6. In an electric controller, the combination of a frame, pairs of relatively movable contacts, means causing one contact of each pair to move toward or .away from the other, conical terminals connected each to one contact of one pair, a member detachable from said frame, spring mounted terminals on said member having conical recesses, and means connecting said member to the frame so as to press respective terminals together.

7. In an electrical controller the combination of a, frame, pairs of relatively movable contacts therein, a plurality of insulated terminals in said fran'ieeach connected to one contact of a pair, a detachable member joined to said frame by bolts, terminals I mounted in said member opposite the terminals in the frame, and spring means intel-posed between the second member and the terminals mounted in it.

8. In aneIectric connecting device the combination of a drum bearing cams, pairs ot contacts ad acent to said drum, terminals connected to said contacts, independent terminals mounted upon a removable member and means pressing the two sets of terminals together.

9. In an electric controller, the combina' tion of a drum bearing cams, pairs of contacts adjacent to said drum, one contact of each pair being movable, a projection on said movable contact adapted to cooperate with a cam on the drum, a casing surrounds ing, said drum and contacts, connectors passing from said contacts through said casing,

and a removable cap bearing contact pieces spring pressed toward said connectors.

10. In an electrical connecting device the combination of a casing, a drum bearing cams rotatably mounted in said casing, pairs of contacts arranged adjacent to said drum and adapted to be pressed together by said CiLIDSyZ, cover upon said casing, insulated terminals mounted in said cover and connected to said contacts, a removable cap, bolts pressing said cap upon said cover, and spring mounted terminals in said cap adapted to abut upon-the terminals in the cover.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN GODFREY PARRY THOMAS.

Witnesses:

WVILLIAM LEWruwAr a, Gnonon LOUNABACII. 

